The weights,in kilograms,of 17 randomly selected adults are given below.Find the interquartile range (IQR)by hand. 65.3 74.8 84.8 64.9 54.0 59.9
57.6 70.8 81.2 72.1 81.6 91.6
51.7 66.2 68.5 76.2 78.5
A)21.3 kg
B)51.7 kg
C)17.5 kg
D)13.6 kg
E)39.9 kg

Question

Quizplus · Accepted Answer

To find the IQR, we first need to find the median of the dataset.

Arranging the dataset in ascending order: 
51.7, 54.0, 57.6, 59.9, 64.9, 65.3, 66.2, 68.5, 70.8, 72.1, 74.8, 76.2, 78.5, 81.2, 81.6, 84.8, 91.6

The median is the middle value of the dataset, which is the average of the two middle values since there are an odd number of values:

Median = (72.1 + 74.8)/2 = 73.45

To find the quartiles, we need to find the medians of the two halves of the dataset:

Lower quartile (Q1) = median of the lower half of the dataset 
Q1 = (59.9 + 64.9)/2 = 62.4

Upper quartile (Q3) = median of the upper half of the dataset 
Q3 = (81.2 + 81.6)/2 = 81.4

Now, we can find the IQR by subtracting Q1 from Q3:

IQR = Q3 - Q1 = 81.4 - 62.4 = 19

Therefore, the correct answer is (C) 17.5 kg.

The Weights,in Kilograms,of 17 Randomly Selected Adults Are Given Below